Commentaries on Directions That Will Impact the Future of Technology

Archive for the tag “Electric vehicle”

The holy grail of the electric car business is a competitively-priced vehicle that will travel several hundred miles on a single charge. As shown in the graphic, we ain’t there yet. One key to finding that grail is battery technology. A little-known Silicon Valley company called Envia Systems claims to have made tremendous strides in developing a battery technology that will lead the industry directly to that grail – pass Go, collect $200.

The operative measure for vehicle battery technology is Wh/Kg, or Watt-hours per Kilogram. Current technology, like that used in Tesla Motors‘ cars, is around 240 Wh/Kg and costs roughly $200 per Kilowatt-hour. Envia promises to deliver 400 Wh/Kg at $125 per Kilowatt-hour. With those numbers, a $20,000 car could travel 300 miles before it needs to be recharged.

In general, battery technology improvement appears to be advancing at a rate of 5% a year. If Envia’s claims are valid, its technology nearly doubles state-of-the-art energy density at half the cost. Lots of folks are excited by the possibilities, including General Motors which has invested a bunch of money into the venture.

Envia began its journey in 2007 when it licensed some patents from Argonne National Laboratory (ANL). Although Envia execs claim that the Envia technology was developed on its own, the Argonne patents gave it a start. Although the details of the patent agreement are secret, apparently ANL will share in Envia’s success if and when it happens.

Envia’s batteries are Lithium-Ion. (Li-ion), the same used in cell phones and portable electric tools. Envia’s technology is based on using unique element chemical compositions for the anodes and cathodes, notably silicon and carbon, and an electrolyte that is stable at high temperatures. Not all the problems that need to be solved have been solved, however. Current tests show that, although Envia batteries can be recharged to 80% capacity after 400 charges, that number needs to be 1000 to last 300,000 miles, considered to be the average lifetime of a car.

Envia’s technology lends itself to conventional manufacturing processes. The company plans to license it rather than go into the manufacturing business itself. Possible licensees includes General Motors and some other high-profile domestic and foreign firms.

As noted above, while battery technology is one key to mass acceptance of electric cars, it is not the only key. Getting those great batteries charged may pose an even bigger barrier. One only has to look at GM’s recent problems with the Volt to get an idea of the challenge. I took my wife’s Chevy into a dealer a few days ago for service. While there, I asked one of the sales guys how Volts are selling. He looked at me and groaned. He said that the tree-huggers were there in force the first few weeks, but now nobody is interested. FYI, I live in an area heavily populated by tree-huggers!

If you live in California or a few other states that have traffic signals that are switched by vehicles, you already know about induction. You also know about it if you use an electric toothbrush. Transmitting electricity by induction has been around a long time and the phenomena is well understood by electrical engineers. If you want to read about how it works, click here. Basically, there parts consist of a transmitting coil and a receiving coil. In the presence of a magnetic field, current travels between the coils wirelessly.

Today, there are two major efforts afoot with regard to inductive charging. One primarily concerned with cellphones and the other for electric cars. The technology for cellphone charging is based an established standard called Qi (pronounced “chee”) adopted by the Wireless Power Consortium (WPC), and industry standards group. Although there are some inductive charging systems available for cars, there is no industry standard. However, the Society of Automotive engineers (SAE) expects to have one by 2014.

The differences between charging a cellphone and charging a car are vast. All you need for a practical cellphone system is a couple of watts transmitted over a very short distance – inches. A practical system for a car requires kilowatts transmitted over as much as several feet.

The systems available for phones now consist of a pad (transmitting coil) that is wired to a power source and a “case” that encircles the phone (the receiving coil). Placing the phone in the case on the pad charges the phone. In the future, phones will be manufactured with the receiving coil built-in, so the case won’t be needed. If the phone supports Qi, then one Qi pad that will suffice for any Qi-enabled device. The charger from battery company, Energizer, is a good example of the current state of the art.

Personally, I find it difficult to get excited about inductive charging of cell phones. With the current state-of-the-art, it takes 2-4 times longer to charge a phone than with a car or wall charger. That time differential will surely improve, but still it’s not very compelling. The most interesting system I’ve seen is one from Oregon Scientific that puts the pad into a clock. If you need a clock, and many people do, then why not have an inductive pad too?

The car charger is much more interesting to me. It will be possible (and technically feasible) to put transmission pads under roadways, say at stoplit intersections. While you are waiting for the light to change, your car’s batteries could be charging, and your credit card could automatically be debited for the cost! In addition, there is some significant economic muscle behind inductive charging. The Korean, Japanese, and German auto companies are pushing the technology, not to mention Chrysler, Ford, GM and even Tesla!. It is going to happen. Pick a car manufacturers name, couple it with “inductive charging” and Google or Bing the words. You’ll be flooded with hits.

In summary, inductive charging technology, something that has been around for decades is going to be a very big deal!~